package org.apache.maven.lifecycle.internal;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import org.apache.maven.project.MavenProject;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * Handles all concurrency-related logging.
 * <p/>
 * The logging/diagnostic needs of a concurrent build are different from a linear build. This delta
 * required to analyze a concurrent build is located here.
 * <p/>
 * NOTE: This class is not part of any public api and can be changed or deleted without prior
 * notice.
 * 
 * @since 3.0
 * @author Kristian Rosenvold
 */
public class ConcurrentBuildLogger {
  private final long startTime;

  private final Map<MavenProject, Thread> threadMap = new ConcurrentHashMap<MavenProject, Thread>();

  public ConcurrentBuildLogger() {
    startTime = System.currentTimeMillis();
  }

  List<BuildLogItem> items = Collections.synchronizedList(new ArrayList<BuildLogItem>());

  public BuildLogItem createBuildLogItem(MavenProject project, ExecutionPlanItem current) {
    threadMap.put(project, Thread.currentThread());
    BuildLogItem result = new BuildLogItem(project, current);
    items.add(result);
    return result;
  }

  public String toString() {
    StringBuilder result = new StringBuilder();
    for (Map.Entry<MavenProject, Thread> mavenProjectThreadEntry : threadMap.entrySet()) {
      result.append(mavenProjectThreadEntry.getKey().getName());
      result.append(" ran on ");
      result.append(mavenProjectThreadEntry.getValue().getName());
      result.append("\n");
    }

    for (BuildLogItem builtLogItem : items) {
      result.append(builtLogItem.toString(startTime));
      result.append("\n");
    }
    return result.toString();
  }

  public String toGraph() {
    StringBuilder result = new StringBuilder();

    Map<MavenProject, Collection<BuildLogItem>> multiMap = new HashMap<MavenProject, Collection<BuildLogItem>>();
    for (BuildLogItem builtLogItem : items) {
      MavenProject project = builtLogItem.getProject();
      Collection<BuildLogItem> bag = multiMap.get(project);
      if (bag == null) {
        bag = new ArrayList<BuildLogItem>();
        multiMap.put(project, bag);
      }
      bag.add(builtLogItem);
    }

    result.append("digraph build");
    result.append(" {\n ");

    for (MavenProject mavenProject : multiMap.keySet()) {
      final Collection<BuildLogItem> builtLogItems = multiMap.get(mavenProject);
      result.append("   subgraph ");
      result.append(mavenProject.getArtifactId());
      result.append("   {\n");

      for (BuildLogItem builtLogItem : builtLogItems) {
        result.append(builtLogItem.toGraph(startTime));
      }

      result.append("\n   }\n");
    }

    result.append("\n}\n ");
    return result.toString();
  }

}
